Wayyy back in Red/Blue, I preferred offensive attacks to defensive. As long as I was doing a little damage each turn, I just didn't care. Trainers in RBY had infinite PP, so stalling was... pretty much not worth it, heh.
As the generations came and went, though, I found my playstyle changing because the AI slowly became smarter... And the infinite PP aspect got nerfed, which made stalling more viable.
Back to the present, in Black/White... It depends on the Pokemon. Some I use to stall, others I use as attackers. It depends on the Pokemon's stats, nature, and moves.